Cloud-Hosted PBX Development

I am looking for a skilled developer to assist with the development of a Basic VoIP Hosted PBX system to work with SIP protocol with minimal features initially. The project requires the following specific features:

-Call forwarding
-Call Blocking
-IVR
-Ring group
-Extensions
-Call Schedule & Call Queue
- Call recording
-Greetings
- Auto attendant

I also need guidance on specific integrations and customizations for the VoIP Hosted PBX.

The preferred platform for the development is Asterisk.

Ideal skills and experience for this project include:
- Proficiency in VoIP technologies and protocols
- Experience with Asterisk or similar platforms
- Knowledge of call forwarding, call recording, and auto attendant features
- Ability to provide guidance and recommendations for integrations and customizations.